Kendra Harrison, 23, barely missed the cutoff for Team USA this year, but responded by resolving to break the world record in the 100-meter hurdle—and on July 22, she succeeded. Running at the London Athletics Grand Prix, the clocks first showed Harrison running a disappointing .38 seconds slower than the record. Then, to everyone's surprise, officials fixed the clocks. Harrison had run the event in 12.20 seconds, beating Yordanka Donkova's 28-year-old record by .01 seconds.